This invention relates to fasteners. It is primarily concerned with fasteners for sinks or basins which are set down into an aperture in a worktop, the rim being a flange that rests on the periphery of the aperture and which is clamped in place by devices fitting underneath the sink or basin.
The invention is a development of the fastener described in our Patent EP-B-0128772.
That fastener has a clip for attachment to a rail and a hinged clamping member which is tightened up against the underside of the worktop by a screw. This threads through the hinge pin, and when undone allows the clamping member to swing back to and stay in an inoperative position where it will clear the edge of the hole of the worktop as the unit is lowered in. Doing up the screw causes the clamping member to swing and project a portion under the worktop. The clamping member has guide fingers which engage diametral slots in the ends of the hinge pin.
We have now developed a plastics clip to replace the metal one of earlier models and this allows for some improvements. In particular, reliance now does not now have to be placed entirely on the hinge pin for engagement by the screw, and more certain operative and non-operative positions for the clamping element can be held. In particular, when swinging the clamping element into the ready-to-use operative position, correct alignment for the arms of the clamping element to move upwardly can be automatically obtained.
According to one aspect of the present invention there is provided a fastener for holding basins or sinks in worktops, the fastener comprising a clip for engagement with a formation on the underside of the basin or sink adjacent the periphery thereof, a clamping element hinged by a pin to the clip to be engageable under the worktop or to be swung clear thereof when the basin or sink is positioned therein, and a screw engaged through the pin and with the clamping element by which that element can be urged upwardly, wherein the aperture in the pin is not screw threaded but has at least one flexible tag for co-operating with the screw thread, whereby the screw can be retained by pressing it axially into the aperture for the tag to snap over at least one turn of its screw thread, and wherein the clip is of plastics material and presents a non-threaded bore into which the screw self-taps when the fastener is tightened.
Preferably, several tags, for example four, are regularly spaced circumferentially of the aperture
Thus, all the pin does, apart from providing the facility for hinging, is to hold the screw lightly, and the load when clamping is completed is taken by the engagement between the screw and the bore in the clip.
According to another aspect of the present invention there is provided a fastener for holding basins or sinks in worktops, the fastener comprising a clip for engagement with a formation on the underside of the basin or sink adjacent the periphery thereof, a clamping element hinged by a pin to the clip to be engageable under the worktop or to be swung clear thereof when the basin or sink is positioned therein, and a screw engaged through the pin and with the clamping element by which that element can be urged upwardly, the clamping element having guide fingers parallel to the screw and engaged in diametral slots in the ends of the pin, wherein the clip in which the hinge pin is journalled is of plastics material, and the pin and clip have mutually co-operating detents which allow the pin to rotate but which register the pin in two positions, one the operative position for the clamping element engaged under the worktop with the slots in the ends of the pin upright and the other the non-operative position with the pin rotated to a position where the clamping element is swung clear of the worktop.
Conveniently, the detents are angularly spaced recesses in the pin and a projection into the cylindrical bore through the plastics clip which receives the pin. This projection will be small, sufficient to snap into either recess and positively locate the parts, but small enough to be snapped out again and not to impede rotation significantly.
Preferably, one recess is a groove parallel to the axis of the pin and joining the end slots. There may be two other recesses, symmetrically positioned on either circumferential side of that groove. Only one will actually be used, but it is convenient to have two since it then does not matter which way around the pin is entered.
Instead of the guide fingers merely co-operating with a face of the clip as in EP-B-0128772, the clip preferably has grooves to receive those fingers when the pin is in the operative position.
These aspects of the invention may be combined in a single fastener.